Oil separator for crankcase vapors



Jan. 3, 19'50 H. A. cHUBBucK OIL SEPARATOR FOR CRNKCASE VAPORS 3Sheets-Sheet 1 HORACE A CHUBBUGK.

Filed llarch 7, 1946 INVENTOA 67' d ATTO R NEYS.

Jan.l 3, 1950 OIL Filed March 7, 1946 H. A. CHUBBUCK SEPARATOR FORRANKCASE VAPORS 3 Sheets-Sheet 2 Fig. 4

HORACE A. CHUBBUCK.

Jan. 3, 1950 H. A. cHuBBucK 2,493617 OIL SEPARATOR FOR CRANKCASE VAPORSFiled March '7, 1946 3 Sheets-Sheet 3 HORACE A. CHUBBUCK.

NVENTOR. 67C- Y:

f# VM ATTORNEYS.

l Patented Jan. 3, 1950 UNITED STATES PATENT OFFICE OIL SEPARATDRcorporation of Delaware Application March 7, 1946, Serial No. 652,776

This application relates to internal combustion engine construction andmore particularly to an oil separator designed to prevent loss oflubricating oil in the gasses discharged from the crankcase by acrankcasey Ventilating system, although it is adaptable to' anysituation requiring the separation of a finely dispersed liquidsuspended in an aerosol.

The crankcases of internal combustion engines have for many years beenventilated, a wide variety of expediente having been tried to attain theproper degree of ventilation. Such ventilation is desirable to removecylinder blowby gasses, to prevent thel accumulation in the crankcase ofwater and acids, and to minimize the adverse effects of dilution of the`lubricating oil with unburned fuel.

The rapidly moving parts and high oil pressures used in modern enginesresult in a substantial degree of atomization of the oil and theformation of a comparatively stable aerosol. The ventilation ofcrankcases in the usual manner causes large losses of lubricating oil inthe disperse phase in this aerosol. The prime object of this inventionis to provide an apparatus for breaking the aerosol so that crankcaseventilation can proceed without loss of lubricating oil in thedischarged gasses.

With this and,4 other objects in view, the invention comprises thearrangement, construction and combination of the Various elements makingup the structure described in the specification, claimed in the claimsand illustrated in the accompanying drawings, in which:

Figure 1 is an elevation partially in section of an automobile engineshowing in general the relationship of the oil separator and the engine.

Figure 2 is a central longitudinal enlarged section of the working partsof applicantsl novel oil separator.

Figure 3 is' a central section further enlargedy of a check valve. Thischeck valve is encircled in Figures 1 and 2.

Figure 4 is a plan view of the check valve disc.

Figure 5 is a central section of the separating head taken along theline 4 4 in Figure 6.

Figure 6 is a plan view of the separating head. Y

In applicants invention, advantage is taken l of the engine suction tocreate the subatmospheric pressure in crankcase upon which theventilation depends. ,Referring tov Figure 1, the Ventilating systemcomprises a breather pipe cap FOR CBANKCASE VAPORS Horace A. Chubbuck,Dearborn,

to Ford Motor Company,

Mich., assignor Dearborn, Mich., a

8 Claims. (Cl. 123-119) I0 packed with a filtering material II such assteel wool, and mounted upon breather pipe I2. The breather pipe I2opens into valve chamber I3 which is connected by holes I4 to crankcaseI5. In the crankcase the Ventilating air becomes mixed with crankcasevapors and minute droplets of lubricating oil, becoming in effect ad1lute aerosol in which lubricating oil is the disperse phase. Thisaerosol leaves the crankcase via conduit I6.

Conduit I6 terminates in separator head generally indicated at I1 andbest seen in Figures 5 and 6. Separator head I1 comprises a base plateI8 to which is secured conduit I6 and two curved tubes I9. These curvedtubes are given such a conguration that curved tube ends 2| are paralleland closely spaced. Base plate I8 is further provided with an oil drainaperture 20 for the removal of separated oil.

Considering Figure 2, curved tubes I3 open into separator chamber 22which communicates with annular discharge -chamber 23 through aplurality of openings 24 formed in the periphery of member dividing theseparating chamber 22 and annular discharge chamber 23. Concentric baile25 is so placed that gas flowing through openings 24 will impinge uponthe underside of this baille and deposit thereon any oil droplets whichmay have escaped separation in separator chamber l2. Separator chamber22 is connected to the crankcase by oil return 28 which extends to apoint just above the bottom of the crankcase as shown in Figure 1. Itwill be noted that in normal operation the lower end of oil return 26will always be below the level of the surface of the lubricating oil.

Annular discharge chamber 23 is connected to the intake manifold by twoseparate discharges. The most direct discharge is through passageway 21drilled through the wall of the I intake manifold 28. For reasons whichwill become apparent as the description proceeds, this passageway 2l ispartially closed by plug 29 having an axial metering orifice 30. Thesecond discharge from annular discharge chamber 23 into intake manifold28 is by way of conduit 3|, check valve 32 and conduit 33 into shell 34of air cleaner 35 and thence into the intake manifold 28 via carburetor38. Check valve 32 comprises an upper tting 31 threaded into alowertting 38 which in turn is threaded into boss 39 in intake manifold 28.This check valve permits vapors to pass only in an upward direction.This action is caused by disc 40 which rests upon upper face Il of lowerfitting 38. The action of disc I is immediately apparent fromv aconsideration of Figure 4. This figure is a plan view of the disc 40,showing its configuration.

The operation of the device described above is detailed herewith. Theventilating air is drawn into breather pipe I2 through a breather pipecap IIIV which is provided with a. fibrous iltering material II. Thisbreather pipe I2 opens into valve chamber I3. From valve chamber I3 theventilating air enters the crankcase I5 through holes I4. Theventilating air becomes mixed in the crankcase with crankcase vapors andfinely atomized oil droplets and is discharged through conduit I6 intothe oil separator I1. In oil separator I1 the mixture of air, crankcasevapors and oildropletsis received into curved tubes I9. The restricteddiameter of these tubes imparts to this mixture a high velocity. Thesetubes divide the oil bearing mixture into two streams which are thenimpinged upon each other at high velocity. The resulting impacts of theoil droplets upon each other and upon the metal parts results in acoalescense of the minute suspended droplets into larger dropletscapable of settling out under the inuence of gravity in the relativelyquiescent conditions prevailing in separator chamber 22 which receivesthe discharge from curved tubes I9. The oil so removed collects in thebottom of separator chamber 22 and is discharged into the crankcase byoil return 26. The discharge from tubes I9 and any oil which escapedseparation in separator chamber 22 flows through holes 24 and isimpinged upon bafIle 25 before flowing into discharge chamber 23. Batlle25 serves to remove residual oil droplets from the discharge.

Annular discharge chamber 23 discharges the oil free gases andventilating air into the intake manifold 28 via one of two distinctpaths, the choice of paths being dependent upon the operating conditionsat the moment.

During normal engine operation when there is a substantial vacuum inintake manifold 28, annular discharge chamber 23 is discharged into theintake manifold 28 through passageway 21 which is partially closed byplug .29 having an axial metering orifice I0. During this normaloperation check valve 32 will remain closed and prevent an excess of airfrom entering annular discharge chamber 23 and destroying the vacuumtherein.-

During operation under heavy load, the pressure at the opening ofpassageway 21 so closely approaches atmospheric pressure that thedifferential is insumcient to cause a proper ilow of air through thecrankcase for adequate ventilation. Under these circumstances checkvalve 32 opens and metering orice 30 is by-passed through theair cleaner35 and carburetor 36 and in this way an adequate flow of ventilating airis insured when under heavy load. i

Care is taken to correlate the size of metering orifice 30 with the sizeand character of the other openings into the crankcase so that apractically complete vacuum in the intake manifold is incapable ofproducing sumcient vacuum in oil separator I1 to draw lubricating oildirectly into the separator through oil return 26 which is, of course,submerged partially in oil. While the precise size of the metering oriceshould be experimentally determined for each design, a diameter of .090inch has been found satisfactory on the current Lincoln engine.

I claim as my invention: v

1'. An apparatus for insuring continuous subatmospheric pressure in aninternal combustion engine comprising a connection from the crankcase tothe air induction system through a branched conduit, one branch'of saidconduit opening directly into the intake manifold on the engine side ofthe butterfly valve through a restricted orifice and another branch ofsaid conduit of substantial cross section opening into the air inductionsystem. on the atmospheric side `of the butterfly valve and containing acheck valve biased to permit ilow only toward the atmospheric side ofthe air induction system.

2. An apparatus for the recovery in bulk of finely divided oil dropletssuspended in the gasses discharged from an internal combustion enginecrankcase comprising an oil separator chamber communicating with the airinduction system of the engine through a restricted orifice opening intothe intake manifold on the engine side of the butterily valve and alsocommunicating with said air induction system through a conduit ofsubstantial cross section openingv into said induction system on theatmospheric side of the 1 butterfly valve and containing a check valvebiased to permit flow only away from the oil separator chamber, and saidoil separator chamber communicating with the crankcase by means of aconduit the discharge end of which is below the normal level of thelubricating oil, the size of said orifice, the size of all openings fromthe crankcase to atmosphere andv the height of the oil separator chamberabove the lever of the lubricating oil being so fixed that asubstantially perfect vacuum in the intake manifold will not 'cause a owof oil from the crankcase into the oil separator chamber via the oildischarge confinely divided oil droplets suspended in the gassesdischarged from an internal combustion engine crankcase comprising anoil separator chamber communicating with the air inductionV system ofthe engine through a restricted orifice opening into the intake manifoldon the engine side of the butterfly valve and also through a conduit ofsubstantial cross section opening into said system on theatmosphericside of the buttery valve and containing a check valve biasedto permit flow only away from the oil separator chamber, said chamberalso communicating with the crankcase by means of a conduit opening into-the crankcase at a point above the oillevel and terminating within theoil separator chamber in a n plurality of narrow tubes bent so thattheir discharge ends are opposed, parallel and closely spaced, and saidchamber also communicating with the crankcase by means of a'conduit thedischarge end of which is below the normal level of the'lubricating oil,the size of the said orice, the size of all openings from the crankcaseto atmosphere and the height of the oil separator chamber above thelevel of the lubricating oil being so iixed that a substantially perfectvacuum in the intake manifold will not cause a'ow of oil from thecrankcase into the oil separator chamber via the oil discharge conduit.

4. In the process of ventilating a crankcase, the step of dividing theeilluent gas from the crankcase among a plurality of constricted tubesand impinging the gas streams from these tubes upon each other.

5. In a crankcase ventilating apparatus a conduit adapted to conduct theeilluent gasses. said conduit being divided at its downstream end into 5a plurality oi restricted tubes the ends oi which oppose each other anda separate conduit connecting the crankcase with a chamber containingsaid restricted tubes.

6. The method of breaking an aerosol comprising impinging upon eachother a plurality of rapidly moving streams of said aerosol andimmediaiely reducing the velocity of the gaseous phase of the aerosolbelow a point at which the resulting coalesced particles of the dispersephase will be entrained.

7. An apparatus for breaking an aerosol comprising means for impingingupon each other a plurality of rapidly moving streams of said aerosoland means for immediately reducing the velocity of the gaseous phasebelow a point at which the resultingv coalesced particles of thedisperse phase will be entrained. A

8. The method of recovering in bulk iineiy divided liquid fromsuspending gas comprising impinging upon each other high velocitystreams of the suspending gas carrying the ilnely divided liquid so asto coalesce the particles oi liquid and separating the coalesced liquidfrom the suspending gas by reducing the velocity oi such gas 'below apoint at which said coalesced particles will be entrained.

Homes: A. vcHUnnUc-x.

asm-:annees CITED The following references are oi' record in the ille oithis patent.:

UNITED STATES PATENTS

